[GHC] #14972: MacOS panic on TH

[GHC]

#14972: MacOS panic on TH
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        Reporter:  harpocrates       |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.4.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4553
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"2534164aefd346c7c51b70e8e8c49aa881dd9f85/ghc" 2534164/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="2534164aefd346c7c51b70e8e8c49aa881dd9f85"
 Move gmp/config.mk.in to config.mk.in, fix #14972

 Here's how the rube goldberg machine triggered the old bug:

 1. If you have a file gmp/config.mk.in, then Cabal will
 create a generated file in $DIST/build/gmp/config.mk

 2. When you attempt to load inplace integer-gmp via GHCi, it will
 ask gcc (aka clang on OS X) for the file name of 'gmp', with
 base directory set to $DIST/build

 3. There is a folder named 'gmp', and so this folder is returned
 as the 'library' for gmp

 4. GHCi loadArchive chokes to death trying to open a library
 that is actually a folder

 This patch solves the problem by breaking the chain at (1): if we
 don't put config.mk in a folder named gmp, NO PROBLEM.

 Signed-off-by: Edward Z. Yang <ezyang at fb.com>

 Test Plan: validate

 Reviewers: angerman, hvr, bgamari

 Reviewed By: angerman

 Subscribers: erikd, thomie, carter

 GHC Trac Issues: #14972

 Differential Revision: https://phabricator.haskell.org/D4552
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14972#comment:12>
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